function [lIndex,record] = randomStrategy(x, y, l_ind, records, models, i)
%FUNCTION `randomStrategy` randomly select an unlabeled data and add label
%           to it
    %%curLen = numel(l_ind);
    tmp = setdiff(randperm(numel(x)), l_ind{i});
    lIndex = [l_ind{i}, tmp(1)];
    record = cell(1, size(models, 2));
end